Sealants for automobile fuel have been desired to have fuel oil resistance capable of preventing fuel oil leakage from fuel tanks and the like perfectly. Until now, a fluororubber has been mainly used as a sealant component. In addition to gasoline which is a hydrocarbon fuel generally used, oxygen-containing fuels such as ether, alcohol and the like come to be used from the viewpoints of combustion efficiency etc.
Sealants prepared by increasing the fluorine content can have the fuel oil resistance to the oxygen-containing fuels, but, when the fluorine content is increased, the sealants become inferior in freeze resistance to have a possibility of causing fuel leakage in the cold district in winter. Meanwhile, the fluorine content of the sealants is decreased, the freeze resistance of the sealants is good but the resistance to the oxygen-containing fuel is decreased. It is very difficult for sealants even to satisfy both of the fuel oil resistance and the freeze resistance simultaneously.
On this account, development of sealants having not only excellent heat resistance but also excellent freeze resistance and fuel oil resistance and capable of favorable use as a fluororubber sealant for automobile fuel has been desired.
The present invention is intended to solve the problems associated with the above prior arts, it is an object of the invention to provide a sealant composition suitably used for sealants in positions contacted with automobile fuels such as an injector for automobile fuel and the like by improving the freeze resistance, the fuel resistance and the heat resistance of a fluororubber.
It is another object of the invention to provide a sealant suitably usable as a fluororubber sealant for automobile fuel by improving the freeze resistance, the fuel resistance and the heat resistance of a fluororubber.